Common Gartersnake (Thamnophis sirtalis)

As their name suggests, this species is Wisconsin's most abundant snake. They are found in every county of the state and in nearly every habitat type, although they have a preference for forest and woodlot edges and rely heavily on open canopy wetlands for overwintering. They may occasionally be found communally "denning" in very large numbers. Females are generally much longer than males and may occasionally exceed 30" in length. Common gartersnakes look much like other gartersnakes except that their lateral stripes only involve scale rows 1, 2 and 3. Their diet includes frogs, toads, salamanders, fish, earthworms and insects.

This species has a subspecies in extreme southeastern Wisconsin called the Chicago gartersnake that looks quite similar to the common gartersnake.